Impact of Solute Molecular Properties on the Organization of Nearby Water: a Cellular Automata Model
Digest Journal of Nanomaterials and Biostructures Vol. 7, No. 2, April - June 2012, p. 469 - 475 IMPACT OF SOLUTE MOLECULAR PROPERTIES ON THE ORGANIZATION OF NEARBY WATER: A CELLULAR AUTOMATA MODEL C. MIHAIa, A. VELEAb,e, N. ROMANc, L. TUGULEAa, N. I. MOLDOVANd** aDepartment of Electricity, Solid State and Biophysics, Faculty of Physics, University of Bucharest, Romania bNational Institute of Materials Physics, Bucharest - Magurele, Romania cDepartment of Computer Science, The Ohio State University - Lima, Ohio, USA dDepartment of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University - Columbus, Ohio, USA e"Horia Hulubei” Foundation, Bucharest-Magurele, Romania The goal of this study was the creation of a model to understand how solute properties influence the structure of nearby water. To this end, we used a two-dimensional cellular automaton model of aqueous solutions. The probabilities of translocation of water and solute molecules to occupy nearby sites, and their momentary distributions (including that of vacancies), are considered indicative of solute molecular mechanics and hydrophatic character, and are reflected in water molecules packing, i.e. ‘organization’. We found that in the presence of hydrophilic solutes the fraction of water molecules with fewer neighbors was dominant, and inverse-proportionally dependent on their relative concentration. Hydrophobic molecules induced water organization, but this effect was countered by their own flexibility. These results show the emergence of cooperative effects in the manner the molecular milieu affects local organization of water, and suggests a mechanism through which molecular mechanics and crowding add a defining contribution to the way the solute impacts on nearby water.
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